import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Scanner;

public class Transformer {
    public static int[] transform(int[] array){
        for(int i = 0; i < array.length; i++){
            array[i] = array[i] * 2;
        }
        return array;
    }

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int[] array = {1, 2, 3, 4};
        int[] ret = transform(array);
        for (int x: ret) {
            System.out.print(x + " ");
        }
        String rett = Arrays.toString(ret);
        System.out.println(Arrays.toString(ret));
    }
}
